Syrian forces advanced Sunday towards the city of Zabadani near the Lebanese border, killing 20 rebels, according to the state news agency SANA.

Military units backed by the Lebanese Hezbollah group captured three new areas in Zabadani, in their effort to recapture the key city, northwest of capital Damascus and near the Lebanese border.

As many as 20 jihadists died while attempting to sneak out of Zabadani Sunday, just a day after military forces ambushed 40 rebels in the area.

Meanwhile, the Syrian Observatory for Human Rights said that Syrian warplanes carried out eight strikes against rebel posts in Zabadani, in addition to dropping crude barrel bombs on the city.

Syrian ground forces also fired eight surface-to-surface missiles targeting the city amidst intense battles, according to the Observatory.

Government forces aim to clear the city as well as the entire Qalamoun region from the Nusra Front along with its allied militants, who use the city to smuggle militants and armor from Lebanon into the western countryside of Damascus.

If Syrian forces and Hezbollah win the battle they would effectively shield the Lebanese border from the Nusra Front threat, amid reports that several recent blasts targeting Lebanon were planned by Syrian rebels through booby-trapped cars in Qalamoun.